1. Field of the Invention
The present invention generally relates to a climb assist system and, more particularly, relates to a climb assist system adapted for installation in locations providing limited access space.
2. Background of the Invention
The present invention provides a climb assist system which may be readily mounted to an existing fall prevention system, such as may be found on a vertical, generally planar climbing structure, such as a ladder or similar vertical structure. Initially, the distinction between a fall arrest system and a climb assist system should be noted. A fall arrest system generally includes a rope or cable extending along a climbing structure for receiving a rope grab attached to a person, where the rope grab will immovably engage the rope or cable if a downward force is applied to an actuator of the rope grab, such as may occur when a person begins to fall from the climbing structure. In contrast, a climb assist system generally provides an upward force, such as from a counterweight attached via a rope or cable to a person to assist the person in ascending or descending the climbing structure. The counterweight provided by the climb assist system may facilitate slowing a person's descent, should the person fall from the climbing structure, but generally may not provide the safety of a fall arrest system to prevent or arrest the continued fall of a person from the climbing structure.
In recent years, a growing use of installations comprising elevated structures supporting equipment requiring maintenance, has resulted in an increased desirability to provide a climb assist system to facilitate access to the equipment. One such installation comprises wind tower installations in which wind driven turbines are mounted at the top of towers. Such wind tower installations are being designed to increasing heights in a continuing effort to place the wind turbine on the top of the tower at an optimal location for receiving wind energy. For example, wind towers are now often constructed to heights exceeding 200 feet, and the wind towers may typically be grouped together in wind turbine farms, some of which may include hundreds of wind turbines. Maintenance of the wind turbines themselves requires experienced workers that typically have an expertise in working on electrical equipment. Further, maintenance of multiple wind towers in a wind turbine farm may require a worker to climb several towers each day which, when combined with the increasing height of the towers, may contribute to worker fatigue.
One proposed climbing aid for assisting a climber's ascent within a wind tower is noted in WO 2004/071930 A2. A counterweight is disclosed attached to a climber via a system of pulleys for counterbalancing the climber's weight to thereby assist ascent of the climber.
One difficulty in designing a system for installation in a wind tower relates to the particular construction of wind towers in which a plurality of platforms are provided in the ascent from the ground to the top of the tower. A slot or hole is provided through each of the platforms for a ladder and for allowing a climber to pass upwardly or downwardly through the platforms; however, the platforms pose a difficulty in that they may restrict passage of a counterweight or a modification of the platforms may be required to accommodate a counterweight.
It would be desirable to provide a climb assist system for a wind tower that may be installed without modification of the platform structures, and that may be implemented in a compact form so as to avoid intrusion into the operable space of a climber using the ladder.